One type of container for liquids in common use is of the flexible or bag type commonly known as a "bag in the box". In that container, a dispensing closure valve is attached to the bag for dispensing the contents, such as milk or, more commonly, wine. Another type of beverage package is constructed of a leak proof cardborad aluminum foil laminate. The dispenser valve is attached to the lower portion of the package and is subjected to fluid pressure. The beverage supplier packages the beverage and supplies the local supermarket where the package is placed on the shelves and made available for purchase by the consumer. Following the purchase of the product, the consumer dispenses the beverage into an awaiting cup by simply applying finger pressure to a simple push button or actuator. That action opens the valve; and beverage flows out the spout and fills the waiting cup. Unlike beverage packaging constructions using a cap, even a recloseable cap, one need not pick up and tilt over the container to pour out the beverage.
These products remain on the store shelves until the product is purchased, which could be for some long period. The valve must thus initially have a suitable "shelf life" over which it does not leak. Further the beverage is not always consumed at one sitting, except perhaps in the case of Australians. Hence to be effective, the valve, which is subjected to the hydrostatic pressures of the standing confined fluid, cannot allow any of the confined fluid to seep. Beverage containers of this type are not intended to be re-usable. Consequently when the container is emptied, the package is discarded, whether in the garbage pail or, unfortunately all too often, along the roadside. In those packaged goods applications, the closure valve must necessarily be a low cost element of the beverage package system so as to maintain the product price overall attractive to the consumer. Bronze valves thus do not do in this application.
No matter how effective the valve structure may be as a means to open and close a fluid passage, it must be easy to operate. If it requires too large a force to do so or if the valve is awkward to the grip or touch, the valve is not satisfactory to this use.
The aforementioned needs in a dispensing valve for packaged beverage application, particularly the requirement of low cost, have been addressed previously through the use of plastics and modern injection molding techniques for fabricating the elements of the valve with which those skilled in the art are familiar. Some valve constructions are more effective than others. The reader who wishes to be more fully acquainted with those forms of inexpensive plastic valves that have achieved a degree of acceptability in this application may visit the local supermarket and inspect the existing packaged beverage product.
The patent literature describes injection molded plastic dispensing valves useful in this application. For example the patent to Swartzbaugh U.S. Pat. No. 4,623,077, which issued Nov. 18, 1986, describes a dispensing valve of a construction containing a pushbutton that has a toggle like "snap" action created by a spring like action of a plastic diaphragm. When operated the valve may remain open until deliberate action is taken to re-operate the actuator and close the valve. Other patent literature describes alternative forms of such "toggle" type valves. Although presented in an attempt to avoid one practical difficulty, the difficulty which the consumer faces in holding existing designs of push button valves in the open state, the toggle type valves are unacceptable in my view, a view which I believe may be shared by those in the industry, because of the problem of the consumers inattentiveness. Adults who imbibe too much wine during a party that takes place in a nicely carpeted living room area, for example, could have their senses dulled or their minds distracted. It may be too late to realize that the person forgot to turn off the valve. An expensive carpet may be damaged or someone may have slipped in the liquid and fallen as a result. With no warning label on the packagae, the beverage supplier may fall victim to legal proceedings and be held responsible for the damage caused by the customer's inattentiveness. In the case of children of tender years who may be accustomed to opening a carton or bottle cap and tilting over a milk carton to spill milk into a glass with minimal spillage, use of toggle action type valves could be a messy education.
U.S. Pat. No. 4,386,720 granted June 7, 1983 to Speedie also shows a toggle type valve for a wine container. Speedie suggests welding a plastic membrane over the orifice closing diaphragm, in order to minimize an oxygen migration problem by the addition of a membrane of better material; a device, requiring added manufacturing expense. It should be noted that if the valve actuator in the Speedie valve is not moved far enough to effect the toggle action and the actuator is prematurely released the valve will close. Speedie extends that effect by mentioning the possibility that valve illustrated in the patent may be made self closing, which is in the context of a valve molded ideally in a single piece. One of the more popular self sealing dispensing valves is described in U.S. Pat. No. 4,444,340, granted Apr. 24, 1984 to Bond. That valve structure is essentially a plug made of elastomeric material which acts as a plug on an associated fluid confining chamber. When the plugs shape is distorted by means of a protrusion in the center of the plug, a passage is opened and fluid flows from the associated container and leaks past the distorted area. This type of spigot or valve in my opinion cannot withstand any reasonable pressures which may be exerted upon it as its elastomeric nature has a tendency to flex and leak. Further in actual practice the type of valve shown in Bond is difficult to operate. A waitress who needs to fill wine glasses from a bulk container in the course of business who is required to frequently manipulate this valve may find that she has sore fingers and thumbs; thereafter she might unconsciously influence the customers selection of wine.
Another valve that has achieved wide acceptance is manufactured by Waddington & Duval, Ltd. a company based in England. The valve contains a plug supported on a stem and a spring diaphram push button combination. By manually depressing the pushbutton with the thumb, the plug is moved essentially axially and uncovers an orifice through which fluid passes. And the diaphram spring functions to make this valve self closing. Most users are satisfied with the Waddington valve. It has good flow characteristics, reasonable sealing abilities and is relatively easy to operate. However, this valve is expensive. Its elements are not formed in one piece, but four individual components, if an overcap is included, and three individual components otherwise. Each of the elements are made in a separate molding operation. They must be inventoried and assembled together. Those activities require time, space and people, which adds to the manufacturing cost. Another multipart self closing valve intended for application in a "bag in the box" application is presented in Hyde U.S. Pat. No. 4,687,123.
An object of my invention, therefore, is to provide a self closing valve spout that is of novel and inexpensive structure; It is a further object of my invention to provide a dispensing closure valve for use with packaged liquids that has an acceptable shelf life and does not allow the confined liquid to seep or leak out of the package; It is a still additional object to provide a closure valve that may be more easily manufactured than prior valves that addressed the same application and that can be manufactured from a single piece of plastic material using conventional injection molding technique.